got 2 calls from this # - left no message. Tried to call the # back and it says the # is not in service... ???

How is it we can have federal number block, but these pests can call and BUG us, yet not say who they are.  I personally think if someone owes a bill send them to the address they used a (one!) notice, if they dont reply do what has to be done. DO NOT BOTHER a number you have been told many times not to call.  I am sick, you call I may be in the middle of a medical treatment or sleeping for what?
The people making this call to threaten me...we are not who your looking for!

201-471-9855 called me and would not talk they need to do something about this

called me and hung up as soon as I said "hello"

soo.. telle-marketer? or stalker? same person called me